Before treatment begins participants are evaluated with CT or MRI scans of the head, neck and chest area to determine the extent of the cancer; an electrocardiogram and blood tests; and a neurocardiovascular evaluation that includes measuring blood pressure in different body positions and involves injections of phenylephrine and nitroglycerine. Some patients may undergo a procedure in which a tube is inserted into the larynx (voice box), bronchi (breathing tubes) and esophagus (food tube) and tissue samples removed. This procedure is done under general anesthesia in the operating room.